Sixty years ago this month, the November 1963 issue of Popular Mechanics showed how to make this 8-in-1 project kit. The heart of the unit was a 2N107 transistor. It could be used as a code oscillator, or with the pitch of the oscillator turned way down, it would start clicking and serve as a metronome. It could also be used as a continuity tester, or for making various alarms.